I have tried varieties of L-Tryptophan. Even one compounded by a pharmacist. This version with the Coenzyme B-6 is the most remarkable. I feel better quickly and sleep very well at night. It helps with daily stress and is perfectly safe. Eliminates many cravings for sugar and caffeine. A great investment in my health. Wouldn't be without it.

The inclusion of B6 as p5p was a good choice in conjunction with tryptophan. The Dr. Best formula includes B3 as niacinamide (which is a known soporific agent), but having added my own niacinamide, I cannot perceive any difference.
Melatonin is synthesized AFTER serotonin. The synthesis of serotonin (and other neurotransmitters) is catalyzed by a B6-dependent enzyme. Furthermore, B6 is required to manufacture Niacin from tryptophan.
Thus a reason one might choose tryptophan over melatonin is NOT to skip any intermediary steps (there are a few studies showing that direct melatonin supplementation reduces levels of intermediary products). I use low-dose melatonin anyway (Same brand, sustained release) because sleep is scarce.

My 25 year old son, who suffers from severe schizophrenia symptoms, probably caused by organophosphate poisoning at the age of 8, has been taking L-Tryptophan for 2 weeks and the change in him is remarquable. He has been confined to the house and his bed for years now we are out walking twice a day! The terror of passing people is diminished considerably and the overwhelming wish to die has gone. I hope it is going to last as we tried 5HTP last year with the same effect but it suddenly stopped working and he was thrown back into the hellish pit of schizophrenia.

Tryptophan is much better and much more consistent than melatonin in sleep support, act's much slower but much longer and does not give you same kind of night sweats. Melatonin knocks you out faster and harder but wears off in hour or two, max three. You also get benefits of serotonin and endorphin as your body manufactures also these from tryptophan. For me it is easier to get adequate tryptophan from pills than food at night as my metabolism turns on overdrive and goes through night if I eat too much heavily tryptophan laden food before bed time. Will buy again if there is still a need for sleep aid next time. P5P is a additional bonus on this one, iherb should take 90 or 120 pcs packages into lineup fast.